Method and apparatus for suppressing sparks

Abstract

A spark suppression device includes a plurality of blades or vanes that are mounted transversely in a duct of an air handling / dust collection system communicating with a spark source. A controlled flow of air carries sparks from the spark source through the spark suppression device. Sparks are suppressed by turbulence created in the airstream from the blades that have a downstream curvature. The turbulence strips away a hot air bubble surrounding a spark ember, thereby effectively cooling the spark and significantly reducing combustion at the spark ember. Other attributes of the invention contributing to spark suppression include an overlapping arrangement of the blades that results in high-velocity impact of the sparks against the blades, thereby breaking up the spark embers into smaller embers, and creation of rapid increased pressure within the spark suppression device that also helps to strip away the spark ember from the surrounding hot air bubble.

Description

FIELD OF THE INVENTION[0001]The present invention relates to devices that manage, control, or suppress sparks, and more particularly, to a method and apparatus for suppressing sparks that are produced in industrial processes and become conveyed in air handling systems and dust collection systems.BACKGROUND OF THE INVENTION[0002]There are many industrial processes that result in the production of sparks, either actively, passively or accidentally. Active production of sparks include those processes that generate a tremendous quantity of sparks, for example, welding and plasma cutting operations. Passive production of sparks refers to processes that are known to periodically generate sparks, yet spark production is relatively infrequent, for example a drying process that produces sparks primarily during startup and shutdown periods of operation. Accidental spark production refers to spark generation as the result of an accidental occurrence, for example, sparks are generated by the im...

AI Technical Summary

Benefits of technology

[0009]Another attribute provided by the present invention can be referred to as a “sling-shot” effect or momentum conservation that also helps to separate the spark ember from the hot air bubble. Due to expansion as mentioned above, the airstream velocity on the upstream side of the turbulator decreases rapidly in approaching blades of the turbulator. However, because a spark ember is of much greater density than the surrounding airstream, the ember, in maintaining momentum, separates from the surrounding hot air bubble. Thus, the spark ember is slung forward and away from the slower moving hot air bubble. Therefore, in addition to the increased pressure that helps to strip away the hot air bubble from the spark, the momentum of the spark ember itself also helps to separate the hot air bubble from the spark ember.

[0017]The monolithic design of the present invention has no moving parts that could potentially malfunction, which is most favorable for seeking absolute fire and burn-damage prevention. Being integral to the duct work, the spark suppressor does not rely on any auxiliary power or controls, rather, it is always working whenever the fan of the air handling system is running, which results in 100% spark detection and 100% response to sparks.

Problems solved by technology

Nevertheless, some sparks are indeed large enough and hot enough to be conveyed through ductwork for relatively long distances.

Because spark embers are buoyant due to a bubble or casing of hot air that surrounds each spark, sparks in this size range may travel relatively long distances in ductwork.

Thus, sparks may move at velocities that substantially match the air stream, until the spark is arrested against the filter media.

If a spark is large enough and hot enough, the filter media will ignite, and so too will combustible dust caked on the filter media.

A spark passing through the spark suppressor is subjected to a sudden increased pressure that disrupts the hot air bubble surrounding the spark ember.

Accordingly, the ember / hot air bubble equilibrium is disrupted under the influence of increased pressure and becomes unstable, and the spark ember begins to separate from the hot air bubble.

Images